Brake-operating attachment for motor vehicles



May 4 1926.

F. c. FRANZE N BRAKE OPERATING ATTACHMENT FOR MOTOR VEHICLES Filed July11 Patented May 4, 1926.

UNITED STATES FRANK c. rnnnznn, or ammonia, rumors.

rA'rsNro,

nnm-ornnarme arracmannn'ron moron vnnrpms.

Application filed July 11,

To all whom it may concern:-

- Be it known that I, FRANK C. Fmuznm.

a citizen of the UnitedState's, residing'at Rockford, in the county ofWinnebago and State of Illinois, have lnvented certain new and usefulImprovements in Brake0perating Attachments for Motor Vehicles, of Whichthe following is a specification.

This invention relates in general to brakes and has more particularreference to operating means for brakes applied to the driving wheels ofa.motor yehicle, usually to a. drum on the hub of ach wheel.

The primary purpose of my invention is to provide an improved brakeoperatin device whereby a' powerful brake app'ying I pressure may beexerted with comparatively little manual effort and whereby the brakeapplying pressure will be equalized in its application to both drivewheels of a motor, vehicle. To this end I employ,.in the preferredembodiment of my invention an ar-. 'rangement of brake-connectedlevers,a manually operable pull rod and a double togglejoint connection betweensaid rod and levers whereby first movement increasing and then brakepressure increasing and constant.

equalizing pressure of braking is secured ing action with minimu withthe pull on said rod.

Another purpose is to provide a brakeoperating device of the charactervdescribed 'which may be applied as an attachment motor vehicle forimprovto practically any ing the braking facilities thereof.

manual effort and is especially desirable a safety factor. By this Imean that it lenables the driver to bring the vehicle to stop or toretard its motion. quicker and 'th less effort than with the:conventional brake-operating mechanisms acting on the rear wheels. Myinvention is therefore partfcularly i'iscful and desirable in itsapplication to motor vehicles used in city driving wherefrequent andsudden stopping is necessitated by traffic conditions and also in hillyand mountainous country where the brakes are relied upon for safety vtoan unusual extent.

till another purpose is to provide a brake-operating attachment of thecharacter described so constructed that it may be eas- My inventionenables Ilore efie'ctive brak ily attached to a motor vehicle and willbe driving Wheels.

the drive wheels, providing a service brake 1924. Serial No. 725,321

'tion when censideredin connection with accompanying drawing, in whichFigure 1, is a fragmentary top view of the driving wheel end of therunning gear v of a motor vehicle showing a brake-operat- 5'5 ing deviceembodying my invention appliedthereto; v r Fig. 2, is an enlarged topview of the principal parts of the brake-operating at ta'eih-ment,removed from the running gear; 1 o i i Figs. 3, 4. and 5 arecross-sections taken on the lines 3-3, 4- 4 and 55 respectively of Fig.2.

In illustrating my invention I have taken as an example its applicationto a Ford motor car for operating servicebrakes on the I In thisembodiment theprincipal parts making up my invention are applied as anattachmenttp the running gear, as for example, to the drive shaft tube.or torque tube as it is-commonly known, designated on the drawing b 6.In this case external brake bands 7 are applied to adapted -to beoperated by the foot brake pedal. The particular construction of thebrakinglcmechanism per se for each drive wheel and the-manner in whichit is operated by'pull rods 8 is not important to the present inventionand is here illustrated only in a conventional way because suchmechanisms, are well known in this art and 1 any of variousconstructions might be .employed. My invention com prehend's theprovision of. a device interposed betweena manually operable part suchas a foot pedal and brakeagainst the under side of said tube and is aconnection. I

rigidly clamped thereto by means (if one or more U-bolts 11. Forsimplicity in construction the bracket 9 has formed integrally therewithat its front and rear ends inclined pads 12 by means of whichthe'bracket is properly seated and located on the tube, and a singleU-bolt interposed between these pairs of pads is employed for securingthe bracket'to the tube. .On each rear corner 1 of the bracket ispivotally attached at 13 aibell-crank lever designated generally by 14having a comparatively long outwardly reaching arm 15 connected at itsouter end to the adjacent pull rod-8 and liavinga. rear- 5 wardlyextending shorter arm 16. A metal strap or link 17 connecting the pivotbolts 18 below said levers serves to strengthen the support therefor andto hold the pivot bolts or rivets in parallelism and also to provide a20 guide member for a pull. rod or bar l8. This pull rod, interposedbetween the levers 14Qatits sides and the bracket 9 and guide strap-17at its top and bottom, is free to slide lengthwise with'respect to thebracket 9 and to swing or rocklaterally with respect therefulcrumingagainst either lever '14. Said pull rod 18 will be connected by anysuitable means to a brake pedal (not shown) or any suitable manuallyoperable member 9,101. operating the brakes, said rod having-at presentthe laterally offset forward end which connects by means of arod 19 tothe foot pedal. The rearv end of said pull rod 18 isconnected to therear ends of theilever arms 16 by links 21 wll1ch provide a doubletoggle joint or lazy-tongs structure. For simplicity in construction,one link is position-ed above and the other below the rod or .bar 18 andconcentricallyconnected thereto by means of .a rivet 2'2 providin gapivotal Each link is pivotally connected at its opposite end at 23 tothe rea'ror outer end of theadjacent arm 16. These links'arepreferably'of the same length-asthe link 17 and have their-openingssimilarly located so that the links are interchangeable with n a View tofacilitating construction and assembling of the. equalizer.

By reasonv of the foregoing construction the pressure exerted by theforward pull on the r0d.18 by pressure on the foot pedal or theequivalent, will be increased/by the action of the-toggle joint so thata, powerful 5 brake applying pressure may be exerted by comparativelylittle manual effort. The

equalizer gives a cushioned operation of the 1 foot pedal, that is, thepedal gives easily upon first pressure but the resistance builds oupuntil a point is reached where the wheels 1 are locked. Theinitial:light pressure is cjompanied with a considerable movement l, f the brakeand the only-resistance met with isthat incide'nt to the.taking-up ofthe slack of the brake bands. An inspection of Fig. 2 will show that asthe rod 18 is first meshes pulled the toggle linkage will afford arelatively angular movement of the bell-crank levers 1.4, but as thelinks 21 approach closer and closer to aligned relation a given movement of the rod produces less and less augular n'iovement of thebell-crank levers. T his is ideal from the standpoint of a Wordingincreasing braking pressure the farther the pedal is depressed. Theparts are .propor tioned so that the first onedourth inch movement ofthe foot pedal gives a three-fourths inch movement on the cams at the cndpof; the, brake rods; the .,'next one-eighth'm'ch movement gives aonerfourth inch movement of the brake can'is the nest one-eighth givesone-eighth; inch x norement and theinext oneeighth QIYOS: one-sixteenthinch movement The advantages of this opera-lion will be ap parent. The.mechanical advantage builds up at the tune it is most needed up to apoint where. 1t is. possible to} lock the wheels. Furthern'iore. byreason of the double toggle joint an equalizing action is obtainedwhere- .by the force will beequallv divided between and applied to thebrakebands so that the braking actionwill be substantially"uniform onboth wheels even though the hand adjustments difier. By employing shortand long lever arms on the bell-cranks in a ratio roughly of 1 to 2 fortranslating the motion from the equalizer'to the pull rods 8111cbrake-applying motion is increased with the result that only a shortmovement oflthe pull rod 18 is required. This proportioning of the leverarms together with the toggle links function toproduce the noveloperation above described. This organization of parts isexceedinglysimple and practical and serves the above-mentioned purposes in a verysatisfactory manner.

It will be manifest that; the braking attachment is easy to apply orinstall on the running gear of the vehicle for the reason that only asingle U-bolt is necessary for securing the lever supporting bracket andits connected parts to 'the torque tube and for the further reason thatall slaokness in the connections either forward or rearward of saidbracket may be taken up by adjustment of the bracket on the tube.

It is believed that the foregoing conveys a. cleanunderstanding of theobjects prefaced above and while I have illustrated but a single workingembodiment it should be understood that changes might be made in detailsof construction without departing from the spirit and scope of theinvention as ex-' passing through the pivotal connections of said linkswith saidshort arms. y 2. In a brake-operating mechanism, i combination,a pair of brake-connected levers for a pair of separate wheels, amanually operable-pull rod, and double togglejoint connection betweensaid rod and levers whereby brake pressure increasing and equalizing issecured for the brakes of the two wheelsbya pull on said rod.

v3. A brake-operating attachment for m0- tor vehicles comprising, incombination, a supporting bracket, means for attaching the bracket to adriving shaft tube, a pair of levers pivoted on said bracket, eachadapted for operating one of the brakes, a manually operable pull rod,and a double togglejoint connection betweensaid pull rod and leverswhereby brake pressure increasing v and equalizing is secured.

4. A brake-operating attachment of the character described comprising,in combination, a supporting bracket, a pair of bell crank leverspivoted thereon, a pull bar in-' terposed between said levers, and atoggle connection between said pull bar and levers, said attachmentbeing adapted to be interposed in'connections between a foot pedal andbrake bands on the driving wheels for transmitting'brake pressureincreasing and equalizing by pressureon and movement of the foot pedal.

5. A brake-operating attachment of the character described comprising,in combine tion, a bracket adapted to seat against a driving shaft tube,a U-bolt adapted to embrace-said tube and secure the bracket thereto, apair of bell-crank levers pivotally mounted on the bracket each on anopposite side thereof, each lever having an outwardly extendingbrake-connected arm and a rearwardly extending arm, a pull rodinterposed between said levers, and a link connecting each rearwardlyextending lever arm to said ull rod so as to provide apressure-increasmg and equalizing connection between said pull rod andlevers. 4

6. A brake-operating attachment of the character described comprising,in combination, a supporting bracket, a pair of hellcrank leverspivotally mounted L on said bracket on opposite sides of a center line,each lever having an arm extending out wardly from-its pivot andan armextending rearwardly therefrom, each outwardly (pull bar, v

arm of one of said levers and concentrically pivotally connected to therear end of the pull bar 7 A brake operating attachment of the characterdescribed comprising in combination av supporting bracket, a pair ofhellcrank levers pivoted at opposite sides of said bracket and extendingin opposed relation therefrom, a link connecting the pivotalconnections-of said levers, a pull bar oper-- ating between said bracketand said link between said levers, said levers comp'rising outwardlyextending ,arms and rearwardly extending arms, the rearward end of saidpull bar lying between said rearwardly extend-' ing arms, and a pair oflinks pivotally connecting the end of said pull bar-with the ends ofsaid rearwardly extending arms.

8. A brake operating attachment of the character described comprising incombination a supporting bracket, a pair of hell,- crank levers pivotedat opposite sides of saiii bracket and extending in opposed relatiotherefrom, a pull bar operating between said levers, said leverscomprising outwardly ext; tending armsv and rearwardly extending arms,the rearward end of said pull hair lying between said rearwardlyextendin" arms, and a pair of links pivotally connect? ing the end withsaid pull bar with the en bracket and extending in opposed relationtherefrom, a link connecting the pivotal connections of said levers, apull bar operating between said bracket and said link between saidlevers, said levers'comprising outwardly extending arms and rearwardlyextending arms. the rearward end of said pull bar lying between saidrearwardly extending arms, and a pair of linkspivotally connecting theend of said pull bar with the ends of said rearwardly extending arms,the last mentioned links being approximately of the same length as thelink connecting the pivotal connections of saidlevers.

, F RANK C. FRANZEN.

